1. Field Of the Invention
The present invention relates to a code setting circuit for generating a digital signal which is used by an external circuit for setting a reference value or the like.
2. Description of the Related Art
A code setting circuit as disclosed in Japanese Provisional Patent Publication 4-150050 includes a plurality of thin-film resistors which are selectively burned out by the application of a voltage pulse through respective pad terminals to produce a set of high and low potentials. By using these potentials, a decoder generates a digital setting signal. However, when the voltage pulse is applied to a pad terminal, there is a sharp increase in the impedance of the pad terminal and a noise pulse is generated. Due to this noise pulse, a MOS transistor connected to the pad terminal is destroyed, failing to burn out a desired thin-film resistor.